James wilkinson



J. WILKINSON. LEAD BUSHING.

APPLICATION FILED OCT. 7. I91 6.

Patented May 20, 1919.

Invent or: I James Wilkinson,

His Attorney.

UNITED STATES PATENT OFFICE.

JAMES WILKINSON, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

LEAD-BUSHING.

Specification of Letters Patent.

Patented May 2 0, 19 19.

To all whom it may concern Be it known that I, JAMES WILKINSON, av citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improven'ients in Lead-Bushings, of which the following is a specification.

My invention relates to lead bushings, particularly to those of the oil or compound filled type adapted. for insulating high tension leads where they pass through the walls of oil-filled tanks for electrical apparatus such as transformers and oil switches.

Heretofore, when bushings of the oil filled type have arced or become damaged in such a way that they -must be removed, considerable inconvenience has been experienced because the whole bushing must be removed,

damaged portion of the bushing independently of the other portions.

A further advantage of my invention results from the oil-tight character of the joints of the bushing. The parts of the bushing, or parts of the bushing and the tank or other carrying member for the bushing wall, are directly clamped together, each joint bein provided with its own clamplng devices. has been found that bushings of this character can be made very nearly absolutely oil-tight, considerably more so in fact than the bushings of the type long used but employing a very simple clamping device for each bushing.

For a detailed understanding of my invention, reference may be had to the accompanying drawing, in which Figure 1 illustratesa bushing constructed in accordance with my invention, partly shown in section and partly in elevation; Fig. 2 is a fragmentary section through a bushing embodyin a modified form of my invention.

ferring particularly to Fig. 1 of, the drawing, 5 denotes the casing wall of the electrical apparatus which contains a body. of oil 6 or other carrying member for the bushing. 'The wall 5 has an opening 7 which is covered by inner and outer insu lator cones 8 and 9. These insulator cones may be made of any tough or infusi'ble material, preferably a material which is capable of being molded under high temperature and pressure, such as, for example, bakelite.

The insulators 8 and 9 are provided with flanged base portions 10 and 11, respectively, which. are ground to fit tightly over the opening 7 in the casing wall 5.

In order to secure the insulator cones to the casing 5 in a mannerv so that they can be readily removed, and so that the joints between the cones and the casing may be strictly oil'tight, I provide clamping rings 12 and 13 which fit down snugly over the flanged bases 10 and 11 and are each held in place by a series of bolts 14: secured in the casing wall 5.

In order to rigidly secure these bolts 14in the casing wall 5, I make them in a special form, threaded at both ends with a squared central portion 15 which is adapted to be brought up snugly against the casing wall by nut 16 and lock nut 17. 17, together with the squared portion 15, make an oil-tight joint where the bolt 1e passes through the casing wall 5. The nuts 18 at each end of the bolts 14 engage with clamping rings 12 and 13 to secure them in place.

In order to avoid the turning of a bolt 14 after it is once in place, and thereby preventing the working loose of nuts 18, I provide a squared recess 19 in the under face of clamping rin 13 to enga e with the squared portion 15 0 bolt 14. his affords a convenient and efl'ectual means for preventing any tendency of the bolts 14 to turn or let the clamping rings become loose after the nuts 18 have once been driven into place.

The nuts 16 and i In order to provide an oil-tight joint Wherethe conducting lead 20 passes through the insulating cone 9, I form the lead 20 with an enlarged shoulder 21 for engaging with the inner surface of the cone 9, while over the outer end of the lead I fit the cap 22. The cap and shoulder are brought snugly up against the cone 9 by means of nuts 23, the cone being ground so as to make a tight joint.

It is, of course, obvious to those skilled in the art that .the insulating cones need not be ground in order to make an oil-tight joint where they fit over the opening in the casing wall 5 or where the conducting lead passes through them. Any convenient packing may be used instead, such as a gasket 24, which I have shown in Fig. 2 as a modified form of my invention.-

In order that the lead bushing may be always filled with oil, I provide the inner cone 8 with perforations 25 so disposed as to trap no air therein.

When it is desired to remove either the inner 'or the outer cone, the oil level is first lowered and then the respective clamping ring is removed. This permits the removal of ei-ther'cone without disturbing the other.

While I have described a specific lead bushing embodying my invention, I would have it understood that my invention is not limited to the exact details which I have disclosed, except as defined by the claims hereto annexed.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with a casing wall having an opening therein, of a lead bushing consisting of inner and outer insulating members provided with flanged portions and clamping members for independently securing. each insulating member over the opening in the casing wall.

2. The combination with a casing wallv having an opening therein, of a lead bushing consisting of inner and outer conical members provided with flanged portions, clamping members for independently securing the conical members over the opening in the casing wall and a conductor having clamping means for tightly securing the same in one of said conical members.

3. The combination with the wall of an oil filled casing provided with an opening therein, of conical insulating members provided with flanged portions snugly fitting over said opening, clamping members engaging said flanged portions and a common.

securing means for said clamping members. 4. The combinatlon with a perforated wall of an oil containing casing, of insulating members provided with flanged portions, clamping members engaging said flanged portions, and double ended bolts passing snugly through the casing wall whereby said insulating members are snugly and independently clamped over the perforations in the casing wall.

5. The combination with a perforated wall of an oil containing casing, of inner an outer insulating members provided with flanges fitting over the perforations, said inner members being perforated so as to form with said outer member an oil filled bushing, annular clamping members engaging said flanges, double ended bolts each having a squared central portion and lock nuts for snugly passing said bolts through the casing wall and adapted to independently'secure said clamping members, one of said clamping members being provided with recessed portions for engaging the squared 

